Add Aqua testing

[JoshuaLampert]

I added some automated code quality testing.

[JoshuaLampert]

CI fails because ExplicitImports.jl needs at least Julia v1.7, but we run CI with Julia v1.6. How do you think, we should handle this, @ranocha, @sloede?

[JoshuaLampert]

CI fails because ExplicitImports.jl needs at least Julia v1.7, but we run CI with Julia v1.6. How do you think, we should handle this, @ranocha, @sloede?

Since we run CI on the latest release and on v1.6, we could also add something like

if VERSION >= v"1.7"
    @test isnothing(check_no_implicit_imports(P4est))
    @test isnothing(check_no_stale_explicit_imports(P4est; ignore = (:PointerWrapper,)))
end

[ranocha]

The problem with your last suggestion is that we would still have ExplicitImports.jl in the Project.toml, leading to the same problem. I have just ignored ExplicitImports.jl in my packages supporting Julia v1.6.

[JoshuaLampert]

Ah yes, you're right. I just removed the ExplicitImports.jl regression test then.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 17.80%. Comparing base (5c6bb24) to head (fc54f63).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #116   +/-   ##
=======================================
  Coverage   17.80%   17.80%           
=======================================
  Files           3        3           
  Lines        1427     1427           
=======================================
  Hits          254      254           
  Misses       1173     1173           

Flag	Coverage Δ
unittests	17.80% <ø> (ø)

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[ranocha]

Thanks!

[sloede]

Nice idea!